GB599966A - Improvements in or relating to electric circuit-breakers of the gas-blast type - Google Patents

Abstract

599,966. Gas-blast switches. REYROLLE & CO., Ltd., A., and ALLAN, A. Sept. 24, 1945, No. 24709. [Class 38(v)] Each phase of a three-phase, pneumatically-actuated, gas-blast circuit-breaker intended for out-door use, comprises a main arcing-electrode G surrounded by an insulating bushing G<1>, and current transformers D<1> in a housing D which is disposed co-axially with the bushing G' to form part of a single elongated assembly, the blast being supplied from a common reservoir C and conduit C<1>, to an annular space E<4> between the bushing G<1> and an insulator E<5>, at a point between the poles of the breaker. The breaker is opened by air supplied simultaneously to pistons H<2>, L<6>, but the arm F<4> of an isolator remains locked in engagement with a contact F<1> until the piston H<2> descends to separate an arc-initiating contact H<1> from the arcing-electrode G, whereupon a tripping-link L<8> attached to the piston H<2>, moves a spring-held togglelinkage L<7> through a dead-centre, and thereby allows the piston L<6> to act through an insulating link L<3> and open the isolator. The arc formed at contact G, H<1> is blown through a nozzle J and exhausted to atmosphere through a cooler J<1>, the air-supply being cut off after arc-extinction and the piston H<2> returned by a spring H<5>. The isolator is reclosed by supplying air to the opposite face of the piston L<6>. The three phases are laterally spaced on the reservoir C, which is supported by a pedestal B, Fig. 1 (not shown). The three isolators may be operated by a single piston L<6> through a common transmission member, but each phase has an interlock L<7>, L<8>. A voltage transformer may be mounted on the housing D.